Bitcoin Forum

I got a new MSI Radeon 7870 HD and have underclocked the memory to 750 and upped core to 1200.

Getting 390M at standard clock and 430M with above settings. Problem is regardless of settings, temp runs up to 80C, runs for 10-20minutes then GPU shuts down and hash drops to 400k.

So the newb question is my PSU has two 6 pin connectors Y'd on two separate cables - so total of 4. I'm using one Y'd pair for both required connections on the card. Could this be an issue?  Should I run one 6 pin connector from each cable? 

Feel like I've covered most other possibilities. Any thoughts are much appreciated.

1200 too high....

My 7870 runs stable 24/7 @ 685 Mem/1145 core  65 c  this is  in a case.

What AMD APP are you using. I use 2.5 Because the latest AMD APP (2.7 ?)is a slug with the 7000 series cards.

Y ed cables?....what is Spec of PSU?...850 or above i would hope...I run 1200w corsairs...i like power.

Thanks for response.

I'm running AMD APP 2.8, perhaps that's the problem.

I don't think its an overheating issue now though - I cranked the fan to 100% and used your settings and kept the temp around 67C, but it still kicked the GPU down to 0% usage after about 10 minutes.

May I ask if you're using any extra flags?

Not sure of the Extra flags...unless you refer too...

IN CGminer setting I use for Rig one....The one with the 7870.

GPU 0 = 6870 (Monitor plugged in) (I) Intensity = 7
GPU 1 = 7870  (I) = 16

In MSI afterburner Fans are Linked, and on Auto

GPU 0 = Mem 525 | Core = 1000 | Mhash = 305 | Temp = 68c |Fan % = 65 -75  (this is one of my oldest cards. 24/7 over a year)
GPU 1 = Mem 600 | Core = 1152 | Mhash = 410 | Temp = 70c | Fan %  (Linked to above) Card is only been 24/7 for 3 Weeks :)

Using Win 7 x64
AMD APP = 2.5

Thanks!

Looking around more, perhaps my biggest issue is GUIMiner. Going to see if I can get CGMiner up and going.

Thanks again for giving me some new ideas to try.

In case it helps anyone else, my problem seems to be with guiminer.

Switching to p2pool using cgminer I've not had any issues with GPU usage crashing to 0 or IO errors.  Manually upping fan to 80% also keeping gpu temp around 63. Noisy, but still trying to dial things in.

Still can't figure out how to run deepbit on cgminer to compare with guiminer hash rates. Will figure it out though.

Running all night, I'm showing 413 Mh/s average in CGMiner at I 7 1200/750

Feels like I should be able to push this a bit higher. Curious about current hash rates of other 7870 owners.

I'm getting 430+ Mh/s on GUIMiner on my Gigabyte 7870 at 1225/1090 @68*C

430 is what I'm targeting. What pool are you using w/ GUIMiner?  I still can't solve the problem of the GPU dropping out after 10-20 minutes regardless of setting w/ deepbit.

I'm on BTCGuild

Thanks. Pushing 430 on BTCGuild and running fine in GUIMiner. I can definitely isolate the problems with the hash rate crashing to deepbit specifically.

No issues w/ p2pool in CGminer either.

No problem. I am quite new to this as well so I am sure there is a bit of room for improvement.